1. Field of the Invention
The present invention generally relates to a music tone parameter setting apparatus and a music tone synthesizing apparatus, suitable for an electronic musical instrument or the like. For example, the present invention is applicable to amusement apparatuses such as a game machine and a karaoke machine, household electrical appliances such as a television receiver, computers such as a personal computer, and a system in which these machines and appliances are integrated.
2. Description of Related Art
A conventional electronic musical instrument allows a user to select timbres of piano, cembalo and so on by operating a timbre select switch and the like provided in the electronic musical instrument. Generally, the electronic musical instrument stores the timbre parameters for these timbres. When the user selects a desired timbre, corresponding timbre parameters are set in the electronic musical instrument.
An electronic musical instrument is disclosed in Japanese Non-examined Patent Publication No. Hei 7-129167, in which a plurality of subsets (one subset is hereafter referred to as a scene or situation) of the above-mentioned timbre parameters are stored. Each scene may contain operation states of timbre setting keys operated by the user in place of the timbre parameters. The electronic musical instrument switches the scenes to change the timbre. Further, the electronic musical instrument can create timbre parameters for an intermediate state between the scenes. Namely, in the electronic musical instrument of this type, a timbre to be set with a timbre setting switch or the like is determined by a set of plural scenes and states between these scenes. Therefore, the timbres to be set with the timbre setting switch or the like are hereafter referred to as a timbre set.
In the above-mentioned conventional electronic musical instrument, control for outputting a continuous operational quantity or manipulation amount is arranged. By interpolating timbre parameters associated with plural scenes according to the operational quantity of the control, a desired timbre between the scenes can be obtained. Also, an automatic or programmed interpolation value varying with time may be used instead of the control operational quantity, such that a timbre can be made gradually transient automatically from one scene to another scene.
While some timbre parameters can be expressed in continuous numerical data within a predetermined range, for example, 0 to 127 (the parameters of this type are hereafter referred to as numerical parameters), other timbre parameters are expressed only in several discrete states (the parameters of this type are hereafter referred to as Boolean parameters). The Boolean parameters include those for designating turning on/off of various capabilities, filters LPF, BPF and HPF, monotony and polyphony, and waveforms including sine, triangle, sawtooth, and square.
However, it is impossible for the conventional electronic musical instrument to make a smooth scene-to-scene transition involving such Boolean parameters. To be more specific, changing Boolean parameters during a scene-to-scene transition causes a noise or alters a timbre abruptly, thereby giving a listener unnatural or uneasy impression. Overcoming this problem requires setting of a common Boolean parameter to plural scenes or subsets included in one timbre set. However, this adds constraints to musical expression.